Simple Synthesis of Mite Pheromone β-Acaridial and Its Analogs in the Secretion of Caloglyphus polyphyllae (Acari: Acaridae)

A simple synthesis of β-acaridial [(E)-1], the active principle of the sex, alarm and aggregation pheromone among astigmatid mites, was achieved in 5 steps from 1,2,4-butanetriol 2 in a 19% overall yield. Its analog, β-acariolal 8, was also prepared in a 63% yield by oxidation of the intermediate, β-acaridiol [(E)-7], with pyridinium dichromate (PDC). This synthetic route also gave β-(Z)-acaridiol [(Z)-7] by using a Z-selective base in the Wittig reaction. (Z)-7 was oxidized to give a new monoterpene, β-(Z)-acaridial [(Z)-1], which was detected as a trace component in the secretion of Caloglyphus polyphyllae, together with 8.     

BACE1 (Beta‐Secretase) Inhibitory Phenolic Acids and a Novel Sesquiterpenoid from Homalomena occulta

Four phenolic acids, namely 2‐[(Z)‐heptadec‐11‐enyl]‐6‐hydroxybenzoic acid ( 1 ), 2‐[(6Z,9Z,12Z)‐heptadeca‐6,9,12‐trienyl]‐6‐hydroxybenzoic acid ( 2 ), 2‐[(9Z,12Z)‐heptadeca‐9,12‐dienyl]‐6‐hydroxybenzoic acid ( 3 ), and 2‐hydroxy‐6‐(12‐phenyldodecyl)benzoic acid ( 4 ), and one sesquiterpene, asperpenoid ( 5 ), were isolated from the 95% EtOH extract of the roots of Homalomena occulta, among which 1, 2 , and 5 represent new compounds. Further, the phenolic acids 1 – 4 exhibited BACE1 (β‐secretase) inhibitory activity with IC₅₀ values of 6.23±0.94, 6.28±0.63, 7.93±0.38, and 7.65±0.62 μM , respectively.     

Cytotoxicity and Antibacterial Evaluation of O-Alkylated/Acylated Quinazolin-4-one Schiff Bases

A series of quinazolin-4-one Schiff bases were synthesized and tested in vitro for their cytotoxicity against two cancerous cell lines (MCF-7, Caco-2) and a human embryonic cell line (HEK-293) including their antibacterial evaluation against two Gram-positive and four Gram-negative bacterial strains. Most of the quinazoline-Schiff bases exhibited potent cytotoxicity against Caco-2. 3-[(Z)-({4-[(But-2-yn-1-yl)oxy]phenyl}methylidene)amino]-2-methylquinazolin-4(3H)-one ( 6f ) with the O-butyne functional group displayed three-fold higher cytotoxic activity (IC₅₀=376.8 μM) as compared to 5-fluorouracil (5-FU; IC₅₀=1086.1 μM). However, all compounds were found to be toxic to HEK-293, except for 3-[(Z)-({4-[(2,4-difluorophenyl)methoxy]phenyl}methylidene)amino]-2-methylquinazolin-4(3H)-one ( 6h ) that showed ∼three-fold lower toxicity and higher selectivity index than 5-FU. Structure–activity relationship (SAR) analysis revealed that O-alkylation generally increased the anticancer activity and selectivity of quinazoline-4-one Schiff bases toward Caco-2 cells. The fluorinated Schiff-base generally exhibited even more significant cytotoxic activity compared to their chlorine analogs. Surprisingly, none of the quinazoline-4-one Schiff bases displayed encouraging antibacterial activity against the bacterial strains investigated. Most of the compounds were predicted to show compliance with the Lipinski parameters and ADMET profiles, indicating their drug-like properties.     

Identification and field optimisation of the female sex pheromone of the rice leaffolder,Cnaphalocrocis medinalis in India

Analysis of ovipositor washings from virgin femaleCnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae) of Indian origin by linked gas chromatography and electroantennography indicated the presence of three electrophysiologically-active compounds. These were identified on the basis of their gas chromatographic retention times and mass spectra as (Z)-11-hexadecenyl acetate, (Z)-13-octadecenyl acetate and (Z)-13-octadecen-1-ol with (Z)-13-octadecenyl acetate present in amounts of between 0.25 and 1.5 ng per ovipositor and the other two components at less than 10% of this. Trace quantities of octadecyl acetate were identified by mass spectrometry but no electroantennographic responses were observed to this compound. Field trials conducted with a range of blends of the three electrophysiologically-active compounds showed that blends containing between 5% and 30% (Z)-11-hexadecenyl acetate in (Z)-13-octadecenyl acetate dispensed from either white rubber septa or polythene vials were more attractive to male moths than a virgin female moth. Addition of (Z)-13-octadecen-1-ol reduced attractiveness to male moths in the blends and concentrations tested.     

Identification and field and laboratory tests of the sex pheromone of Cerconota anonella Sepp. (Lepidoptera: Oecophoridae)

The Annona fruit borer, Cerconota anonella Sepp., is a serious agricultural pest in many tropical areas of the world. The identification of an attractant for male C. anonella could offer new methods for pest detection and control. A mixture of compounds extracted from female C. anonella elicited antennal depolarization in the male borer. These compounds were identified as octadecanal, 1‐octadecanol, octadecyl acetate, (Z)‐octadec‐9‐enal (Z9‐18:Ald), (Z)‐octadec‐9‐en‐1‐ol (Z9‐18:OH) and [(Z)‐octadec‐9‐enyl] acetate (Z9‐18:Ac) by one‐ and two‐dimensional gas chromatography–mass spectrometry. In laboratory bioassays, synthetic individual compounds as well as synthetic mixtures were found to be attractive to males. In addition, field tests using Delta traps with 1 mg of the ternary mixture composed of Z9‐18:Ac, Z9‐18:Ald and Z9‐18:OH in the ratio of 1 : 3 : 5 caught as many males as traps containing virgin females. The ternary mixture of Z9‐18:Ac, Z9‐18:Ald and Z9‐18:OH was identified as attractant to C. anonella males and can be used to detect and control populations of this insect in Annonaceae plantations.     

Isolation and Photoisomerization of a New Anthraquinone from Hairy Root Cultures of Sesamum indicum

An unstable anthraquinone was isolated from hairy root cultures of Sesamum indicum after preventing light throughout all experimental procedures. The structure of the (Z)-isomer of a previously isolated anthraquinone was determined to be 2-[(Z)-4-methylpenta-1,3-dien-1-yl]anthraquinone by spectroscopic methods. This compound was readily isomerized to the known (E)-isomer under light.     

Design, synthesis and in vitro evaluation of novel chroman-4-one, chroman, and 2H-chromene derivatives as human rhinovirus capsid-binding inhibitors

As part of an effort to generate broad-spectrum inhibitors of rhinovirus replication, novel series of (E)-3-[(E)-3-phenylallylidene]chroman-4-ones 1a–e, (E)-3-(3-phenylprop-2-yn-1-ylidene)chroman-4-ones 2a and 2b, (Z)-3-[(E)-3-phenylallylidene]chromans 3a–e, and (E)-3-(3-phenylprop-1-en-1-yl)-2H-chromenes 4a–d were designed and synthesized. All the compounds were tested in vitro for their efficacy against infection by human rhinovirus (HRV) 1B and 14, two representative serotypes for rhinovirus group B and A, respectively. Most of the analogues were found to be potent and selective inhibitors of both HRVs, although HRV 1B was generally more susceptible than HRV 14. Mechanism of action studies of (E)-6-chloro-3-(3-phenylprop-1-en-1-yl)-2H-chromene 4b, the most potent compound on HRV 1B infection, suggested that 4b behaves as a capsid-binder probably acting at the uncoating level.     

An aggregation attractant for the sugar-beet weevil, Bothynoderes punctiventris

During our screening studies, attractiveness of a ternary mixture of synthetic Grandlure I [racemic cis‐1‐methyl‐2‐(1‐methylenethenyl)‐cyclobutane ethanol], Grandlure II [(Z)‐2‐(3,3‐dimethyl)cyclohexylidene ethanol], and Grandlure III–IV [(Z)‐ and (E)‐2‐ochtodenal; (Z)‐ and (E)‐(3,3‐dimethyl)cyclohexylidene acetaldehyde] for the sugar‐beet weevil, Bothynoderes punctiventris Germar (Coleoptera: Curculionidae), was observed in field‐trapping tests at several sites in Hungary and Serbia. The mixture attracted both males and females. Later tests revealed that of the components in the ternary mixture, only Grandlure III–IV were responsible for attraction, and the addition of Grandlures I or II in varying percentages had no influence on trap captures. Traps baited with 50–50 000 µg of Grandlure III–IV on rubber or polyethylene dispensers yielded high catches of weevils. When testing synthetic samples enriched in the respective geometrical isomer, Grandlure IV had a tendency of catching more weevils, but differences were not significant from lower catches by a 1:1 Z:E blend or Grandlure III. In gas chromatography–flame ionization detection/electroantennographic detection studies, antennae of both female and male weevils were more responsive to the (E)‐ than to the (Z)‐isomer suggesting a more important role for Grandlure IV. Efforts to verify the presence of Grandlure III or IV in volatiles collected from either sex of live sugar‐beet weevils or body washings with pentane remained inconclusive. Traps baited with Grandlure III–IV can now be used as sensitive and powerful trapping tools in the control of the sugar‐beet weevil.     

Sex pheromones of Phyllonorycter acerifoliella and Ph. heegerella and communication peculiarities in three species of leafmining moths

Females of the leaf miner moth Phyllonorycter acerifoliella (Z.) [=Ph. sylvella (Hw.)] and Ph. heegerella (Z.) (Lepidoptera: Gracillariidae: Lithocolletinae) release their sex pheromone at the beginning of photophase. The periodicity of the `calling' behaviour of Ph. acerifoliella females was established. Three compounds from calling virgin Ph. heegerella females were collected by the Solid Phase Micro Extraction (SPME) technique and identified as (Z)-8-tetradecenyl acetate (Z8-14:OAc), tetradecyl acetate (14:OAc) and (Z)-8-tetradecenol (Z8-14:OH) in the ratio (88±3):(2±0.6):(10±5) by capillary gas chromatography and mass spectrometry. Field trapping experiments demonstrated that the first two compounds are important for the attraction of conspecific males. Z8-14:OAc was found to be attractive when tested separately, while 14:OAc acted as synergist. The attractivity of the three component blend was reduced by 10% admixture of either (E)-10-dodecenyl acetate (E10-12:OAc) or (Z)-10-tetradecenyl acetate (Z10-14:OAc).Field tests of Z10-, Z8- and E10-14:OAc, identified from Ph. acerifoliella females, demonstrated that the first two compounds were essential for the attraction of conspecific males; so both are sex pheromone components. The attractivity of the three component blend of Z10- Z8- and E10-14:OAc was reduced by 10% admixture of (E)-10-dodecenol (E10-12:OH). The following four semiochemical compounds, Z8-14:OAc, Z8-14:OH, E10-14:OAc and 14:OAc, identified from phyllonoryctid females, as well as two sex attraction antagonists for Ph. acerifoliella and Ph. heegerella males, E10-12:OAc and Z10-14:OAc, are new for the family Gracillariidae. The results of field trapping experiments revealed mechanisms ensuring the specificity of the chemocommunication systems in Ph. acerifoliella, Ph. heegerella and Ph. ulmifoliella (Hb.) moths.     

A blend of formic acid,benzoic acid,and aliphatic alkanes mediates alarm recruitment responses in western carpenter ants,Camponotus modoc

Formicine ants in distress spray alarm pheromone which typically recruits nestmates for help. Studying the western carpenter ant, Camponotus modoc Wheeler (Hymenoptera: Formicidae), our objectives were to (1) determine the exocrine glands that contain alarm recruitment pheromone, (2) identify the key alarm recruitment pheromone components, and (3) ascertain the pheromone components that are discharged by distressed ants. In Y-tube olfactometer experiments, extracts of poison glands, but not of Dufour’s glands, elicited anemotactic responses from worker ants. Gas chromatographic-mass spectrometric analyses of poison gland extracts revealed the presence of (1) aliphatic alkanes (undecane, tridecane, pentadecane, heptadecane), (2) aliphatic alkenes [(Z)-7-pentadecene, (Z)-7- and (Z)-8-heptadecene], (3) two acids (formic, benzoic), and (4) other oxygenated compounds (hexadecan-1-ol, hexadecyl formate, hexadecyl acetate). Testing the responses of worker ants in Y-tube olfactometers to complete and partial synthetic blends of these compounds revealed that the acids and the alkanes are essential alarm pheromone components. In two-choice arena bioassays, micro-locations treated with synthetic alarm pheromone recruited worker ants. Acids and alkanes were abundant in the poison gland and the Dufour’s gland, respectively, suggesting that the alarm pheromone components originate from both glands. Moreover, alarm pheromone sprays of ants differed in that all sprays contained formic acid but only some also contained alkanes, implying that ants can independently discharge the content of either one or both glands in accordance with the type of distress incident they experience.     

Synthesis of the Deuterated Sex Pheromone Components of the Grape Borer,Xylotrechus pyrrhoderus

Adult males of the grape borer, Xylotrechus pyrrhoderus, secrete (S)-2-hydroxy-3-octanone [(S)-1] and (2S,3S)-2,3-octanediol [(2S,3S)-2] from their nota of prothoraces as sex pheromone components. Their structural similarity suggests that one of them is the biosynthetic precursor of the other component. In order to confirm the biochemical conversion, deuterated derivatives of both components were synthesized by starting from a Wittig reaction between hexanal and an ylide derived from D₅-iodoethane and ending with enantiomeric resolution by chiral HPLC. The molecular ions of 1 and 2 could scarcely be detected by using a GC-MS analysis, and the labeled compounds showed similar mass spectra to the unlabeled pheromone components. However, several fragment ions, including four deuterium atoms, were observed in the mass spectra of their acetate derivatives, indicating that the conversion could be confirmed by examining a compound with the diagnostic ions after acetylation of the volatiles collected from insects treated with the labeled precursors.     

The effect of methyl salicylate on the induction of direct and indirect plant defense mechanisms in poplar (Populus × euramericana ‘Nanlin 895’)

The objective of this study was to investigate the effect of different concentrations of methyl salicylate (MeSA) on direct defense and indirect defense in poplar cuttings (Populus × euramericana ‘Nanlin 895’). Four defense-related enzyme activities, such as superoxide dismutase (SOD, EC1.15.1.1), oxydoreductases peroxidase (POD, EC1.11.1.7), catalase (CAT, EC1.11.1.6), and polyphenol oxidase (PPO, EC 1.14.18.1), were measured. The results showed that the SOD activities were induced by 1.0 and 10.0 mM MeSA and the POD activities were induced by MeSA. The CAT activity was induced at low concentrations of MeSA but was inhibited by high concentrations, and the PPO activity was affected by 0.1, 1.0, and 10.0 mM MeSA. Furthermore, the volatiles were detected using gas chromatography–mass spectrometry and gas chromatography. Twenty-one volatile compounds were tentatively identified in the emissions from plant leaves. Of these volatile compounds, (Z)-3-hexen-1-ol and cis-3-hexenyl acetate emissions were the highest. (Z)-3-Nonen-1-ol, (E)-2-hexen-1-ol, 1-octanol, (E,Z)-3,6-nonadien-1-ol, β-ionone, and hexadecanamide were six compounds that were only produced after treatment by 10.0 mM MeSA. These results showed that direct and indirect defense mechanisms in poplars were induced by MeSA.     

Changes of volatile flavor compounds of watermelon juice by heat treatment

ABSTRACT

Changes of volatile flavor compounds of watermelon juice by heat treatment were investigated by gas chromatography-olfactometry-mass spectrometry. Although the major volatile compounds in watermelon juice, three aldehydes, three alcohols, and one ketone, did not increase significantly by heat treatment, dimethylsulfide and methional increased in heated juice. These two sulfides were suggested to contribute to the off-flavors in heated watermelon juice.     

Insights into the binding of thiosemicarbazone derivatives with human serum albumin: spectroscopy and molecular modelling studies

4-[(1Z)-1-(2-carbamothioylhydrazinylidene)ethyl]phenyl acetate [Ace semi],4-[(1Z)-1-(2-carbamothioylhydrazinylidene)ethyl]phenyl propanoate [Pro semi] from the family of thiosemicarbazones derivative has been newly synthesized. It has good anticancer activity as well as antibacterial and it is also less toxic in nature, its binding characteristics are therefore of huge interest for understanding pharmacokinetic mechanism of the drug. The binding of thiosemicarbazone derivative to human serum albumin (HSA) has been investigated by studying its quenching mechanism, binding kinetics and the molecular distance (r) between donor (HSA) and acceptor (thiosemicarbazone derivative) was estimated according to Forster’s theory of non-radiative energy transfer using fluorescence spectroscopy. The binding dynamics has been elaborated using synchronous fluorescence spectroscopy, and the feature of thiosemicarbazone derivative induced structural changes of HSA has been studied by circular dichorism, Fourier transform infrared spectroscopy. Molecular modelling simulations explore the hydrophobic interaction and hydrogen bonding which stabilizes the interaction.     

Three Antinematodal Diterpenes from Euphorbia kansui

Three compounds, 20-O-acetyl-[3-O-(2′E,4′Z)-decadienoyl]-ingenol (1), 20-O-acetyl-[5-O-(2′E,4′Z)-decadienoyl]-ingenol (2) and 3-O-(2′E,4′Z)-decadienoylingenol (3), were isolated from Euphorbia kansui under the bioassay-guided method. Each compound showed the same antinematodal activity against the nematode, Bursaphelenchus xylophilus, at a minimum effective dose (MED) of 5 μg/cotton ball.     

Identification of a pheromone blend attractive to Manduca sexta (L.) males in a wind tunnel

Analyses of solvent rinses of the external surfaces of pheromone glands excised from calling female tobacco hornworm moths, Manduca sexta (L.), revealed the presence of the following compounds: (Z)-9-hexadecenal, (Z)-11-hexadecenal, (E)-11-hexadecenal, hexadecanal, (E,Z)-10,12-hexadecadienal, (E,E)-10,12-hexadecadienal, (E,E,Z)-10,12,14-hexadecatrienal, (E,E,E,)-10,12,14-hexadecatrienal, (Z)-11-octadecenal, (Z)-13-octadecenal, octadecanal, and (Z,Z)-11,13-octadecadienal. The two trienals were identified by mass and PMR spectral analyses and by ozonolyses, and their structures were confirmed by synthesis. In a wind tunnel male tobacco hornworm moths exhibit the same behaviors in response to a synthetic blend of all of the components, the gland rinse, or a calling female. Both (E,Z)-10,12-hexadecadienal and (E,E,Z)-10,12,14-hexadecatrienal are required to stimulate males to complete the characteristic behavioral sequence: anemotaxis, approaching and touching the pheromone source, and bending their abdomens in apparent copulatory attempts. The other components of the blend may play more subtle roles.     

Asymmetric hydrogenation of dehydrodipeptides bearing different protecting groups

Summary.  N-[(Z)-N-Benzoyl- or N-boc-(2-fluorophenyl)dehydroalanyl]-(R)- or (S)-phenyl-alanines 1,2,5 and 6 were hydrogenated in the presence of chiral and achiral rhodium complexes. The optical induction is compared to the results obtained using the corresponding esters as substrates. Received November 11, 2001 Accepted January 15, 2002     

Predator–prey interactions: olfactory adaptations of generalist and specialist predators

1 Olfactory responses of the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), a generalist predator, Podisus maculiventris (Say) (Hemiptera, Heteroptera: Pentatomidae) (Pm), and a specialist predator, Perillus bioculatus (F.) (Hemiptera, Heteroptera: Pentatomidae) (Pb) were investigated. Volatiles tested included 20 compounds emitted by undamaged potato plants (Solanum tuberosum), plants that had been artificially damaged, or plants damaged by feeding by CPB larvae. 2 Coupled gas chromatography/electroantennogram detector (GC/EAD) recordings revealed five compounds for which reliable responses were recorded from CPB antennae: (E)-2-hexen-1-ol, (Z)-3-hexen-1-ol, (±)-linalool, nonanal, methyl salicylate, and indole. Both Pm and Pb responded selectively to the same compounds as the CPB with exceptions: (1) (Z)-3-hexenyl butyrate elicited reliable responses for both Pm and Pb, and (2) (E)-2-hexen-1-ol and (Z)-3-hexen-1-ol were inactive for Pm and Pb under these conditions. Dose–response curves showed that CPB was at least 100 times more sensitive to (E)-2-hexen-1-ol than were the predators. Both predators were more sensitive to each of the other compounds than were CPB. Both CPB and Pm were attracted to a five component blend comprising (E)-2-hexen-1-ol, (Z)-3-hexen-1-ol, (±)-linalool, nonanal and methyl salicylate. However, attraction of CPB to the blend occurred only with lower doses of (E)-2-hexen-1-ol and (Z)-3-hexen-1-ol. 3 These results show that the herbivore (CPB) has olfactory receptors which are more sensitive to constitutive host plant volatiles, e.g. green leaf volatiles, while both generalist (Pm) and specialist (Pb) predators are more sensitive to systemic volatiles produced in response to prey feeding. Keywords Colorado potato beetle, constitutive compounds, host plant, induced compounds, olfaction, Perillus bioculatus, Podisus maculiventris, predator, prey, tritrophic.     

Metabolism of (2Z,4E)-γ-Ionylideneethanol and (2Z,4E)-γ-Ionylideneacetic Acid in Cercospora cruenta

[2–¹⁴C]-(2Z,4E)-γ-Ionylideneethanol and [2–¹⁴C]-(2Z,4E)-γ-ionylideneacetic acid were converted by Cercospora cruenta to [2–¹⁴C]-(2Z,4E)-1′,4′-dihydroxy-γ-ionylideneacetic acid and [2-¹⁴C]-(2Z,4E)-4′-hydroxy-γ-ionylideneacetic acid, which are intermediates of ABA biosynthesis in C. cruenta.     

Syntheses of 2-Deoxy-2-[(2R,3S)-2-fluoro-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-D-glucopyranose and Its (2S,3R)-Isomer

2-Deoxy-2-[(2R,3S)-2-fluoro-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-D-glucopyranose and its (2S,3R)-isomer were respectively synthesized from allyl 2-[(2R,3S)-3-(benzyloxycarbonyloxy)-2-fluorotetradecanamido]-2-deoxy-4,6-O-isopropylidene-β-D-glucopyranoside and its corresponding (2S,3R)-isomer. Both target compounds did not activate macrophage, but the (2S,3R)-analogue strongly inhibited the binding of LPS to macrophage.